Arduino: RGB Leds Diagrams & Code

Arduino: RGB LEDs Diagrams & Code Brown County Library

Projects 01 & 02: Blinking RGB LED & Smooth Transition Components needed:  Arduino Uno board  breadboard  RGB LED (common anode)  4 jumper wires  3 220 ohm resistors

Connect long PIN to 5 volts

/* RGB LED 01 : Blinking RGB LED Source: Code modified from Adafruit Arduino - Lesson 3. RGB LED */ int redPin = 11; int greenPin = 10; int bluePin = 9; void setup() { pinMode(redPin, OUTPUT); pinMode(greenPin, OUTPUT); pinMode(bluePin, OUTPUT); } void loop() { setColor(255, 0, 0); // red delay(1000); setColor(0, 255, 0); // green delay(1000); setColor(0, 0, 255); // blue delay(1000); } void setColor(int red, int green, int blue) { // our LEDs consider 255 to be all the way off and 0 to be all the way on // since we're thinking about it the opposite way in our loop, subtract from 255 // if you are using a common cathode RGB LED, erase the next 3 lines of code red = 255 - red; green = 255 - green; blue = 255 - blue;

// set the three pins analogWrite(redPin, red); analogWrite(greenPin, green); analogWrite(bluePin, blue); }

11/2015 Brown County Library Experimenting with more colors Try adding different colors to your blinking pattern. You can copy and paste the code below into the loop function of Project 01 to create a loop of six blinking colors. Try finding a RGB color picker online (such as this one: http://www.rapidtables.com/web/color/RGB_Color.htm) to create your own colors. setColor(255, 0, 0); // red delay(1000); setColor(0, 255, 0); // green delay(1000); setColor(0, 0, 255); // blue delay(1000); setColor(255, 255, 0); // yellow delay(1000); setColor(255, 0, 255); // purple delay(1000); setColor(0, 255, 255); // aqua delay(1000);

11/2015 Brown County Library /* RGB LED 02 : Smooth color transition Source: Code adapted from project found here - forum.arduino.cc/index.php?topic=7933.0 */ int pins[] = {11, 10, 9}; // an array of pins! This is similar to int pin0 = 11; int pin1=10; int pin2=9; long values[3]; // make an array of values but don't give them a value just yet long current_values[3]; // make an array of current values, but don't give them a value yet int short_delay; // time between transition void setup(){ randomSeed(analogRead(0)); // get some unpredictable value to start off our random number generator // otherwise, we'd get the same random numbers each time (boring!) for (int i=0; i <3; i++) { // pins 0 to less than 3 values[i] = random(255); // pick a random number between 0 and 255 for a pin (red, green, or blue) current_values[i] = values[i]; // make our current value the same analogWrite(pins[i], current_values[i]); // set the LED to our initial choice values[i] = random(255); // pick a new random number for our next color } } void loop(){ short_delay = random(3, 9);

for (int i=0; i <3; i++) { if (values[i] > current_values[i]){ // if our new color is a larger number than our current color ... current_values[i]++; // get just a little bit closer to the new color by adding 1 analogWrite(pins[i], current_values[i]); // set the LED to the new current color delay(short_delay); // wait a little bit }

if (values[i] < current_values[i]){ // if our new color is a smaller number than our current color ... current_values[i]--; / get just a little bit closer to the new color by subtracting 1 analogWrite(pins[i], current_values[i]); // set the LED to the new current color delay(short_delay); // wait a little bit }

if (values[i] == current_values[i]){ // if our new color and our current color are the same ... analogWrite(pins[i], current_values[i]); // make sure the LED is set to the new color values[i] = random(255); // pick a new color } } }

11/2015 Brown County Library Projects 03: Mood Light Components needed:  Arduino Uno board  breadboard  RGB LED (common anode)  8 jumper wires  3 220 ohm resistors  10k ohm resistor  light dependent resistor (sometimes called a photoresistor)

11/2015 Brown County Library /* RGB LED 03 : Mood light with photoresistor Source: Code adapted from project found here - forum.arduino.cc/index.php?topic=7933.0 */ int pins[] = {11, 10, 9}; // an array of pins! This is similar to int pin0 = 11; int pin1=10; int pin2=9; long values[3]; // make an array of values but don't give them a value just yet long current_values[3]; // make an array of current values, but don't give them a value yet const int sensor = 7; // the input pin where the sensor (photoresistor) is connected int val = 0; // val will be used to store the state of the input pin int short_delay; // time between transition void setup(){ randomSeed(analogRead(0)); // get some unpredictable value to start off our random number generator // otherwise, we'd get the same random numbers each time (boring!)

for (int i=0; i <3; i++) { // pins 0 to less than 3 values[i] = random(255); // pick a random number between 0 and 255 for a pin (red, green, or blue) current_values[i] = values[i]; // make our current value the same analogWrite(pins[i], current_values[i]); // set the LED to our initial choice values[i] = random(255); // pick a new random number for our next color } } void loop(){ val = digitalRead(sensor); // read input value and store it

// Check whether the input is LOW (no light) if (val == LOW) { // turn RGB LED on

short_delay = random(3, 9);

if (values[i] < current_values[i]){ // if our new color is a smaller number than our current color ... current_values[i]--; // get just a little bit closer to the new color by subtracting 1 analogWrite(pins[i], current_values[i]); // set the LED to the new current color delay(short_delay); // wait a little bit

11/2015 Brown County Library }

} else { // or if the input is HIGH (there is light) digitalWrite(11, HIGH); // set the three LEDs to HIGH (common anode RGB LEDs consider HIGH to be all the way off and LOW to be all the way on) digitalWrite(10, HIGH); // so since we're thinking about it in the opposite way, setting the LEDs to HIGH turns them off digitalWrite(9, HIGH); // if you are using a common cathode RGB LED, change these three lines to say LOW } }

11/2015 Brown County Library Bonus Project: Using Hexadecimal Colors instead of RGB You can also insert hexadecimal colors into your code instead of using RGB. Use a color picker (such as this one: http://www.rapidtables.com/web/color/RGB_Color.htm) and instead use the combination of numbers and letters (for example, the color “sienna” is A0522D). Look at the line of code for sienna below to see an example of how to plug it in. The Arduino knows that it is a hex number because of the “0x” in front of the letters and numbers, so make sure to leave that in!

/* RGB LED 01 with Hex Colors Source: Code modified from Adafruit Arduino - Lesson 3. RGB LED */ int redPin = 11; int greenPin = 10; int bluePin = 9; void setup() { pinMode(redPin, OUTPUT); pinMode(greenPin, OUTPUT); pinMode(bluePin, OUTPUT); } void loop() { setColor(0x4B, 0x0, 0x82); // indigo delay(1000); setColor(0xA0, 0x52, 0x2D); // sienna delay(1000); } void setColor(int red, int green, int blue) { // our LEDs consider 255 to be all the way off and 0 to be all the way on // since we're thinking about it the opposite way in our loop, subtract from 255 // if you are using a common cathode RGB LED, erase the next 3 lines of code red = 255 - red; green = 255 - green; blue = 255 - blue;

// set the three pins analogWrite(redPin, red); analogWrite(greenPin, green); analogWrite(bluePin, blue); }

Learn More! Adafruit Arduino Lesson 3. RGB LEDS https://learn.adafruit.com/downloads/pdf/adafruit-arduino-lesson-3-rgb-leds.pdf 11/2015 Brown County Library